Popularized by Tipping Point, Dunbar’s number suggests that there’s a limit to social cognition. Roughly speaking, 150 people can form a tight social group; any larger and closeness suffers. Inasmuch, we sacrifice intimacy and trade familiarity for breadth. Is there an optimal social mix?

To achieve such feats in friendship, I trade intimacy for connectivity. There are ten people I have always been close with (family included), and another twenty or so that are close friends. Call it thirty.

Using 150 as a benchmark, this leaves 120 slots. Using my 800 Facebook-friends as an indicator of my extended network, this means that 800 fit into those 120 intimate slots. Very roughly speaking, I trade one close friend for 6.67 acquaintances.

By comparison, consider someone like Gary Vaynerchuk or Robert Scoble. Assume each has thirty close friends. Both hit the 5,000-friend limit on Facebook. That’s at least 42 acquaintances per close friend slot. That’s a lot of people. Both are connected to thousands more.

I wonder at what point, between the 800 I have and the 5,000 (and more) they have, can they not keep track of, let alone remember, those acquaintances.

What if I were to try to know — to really know — those 800 people I’m connected with. How far could I get?